There have been conventionally known electro-photographic type image-forming apparatuses such as laser printers and LED printers. Such an image-forming apparatus includes a developing cartridge which includes a developing roller for supplying toner. Such conventional image-forming apparatuses are disclosed in prior arts.
An image-forming apparatus disclosed in a prior art includes a drum unit provided with a photosensitive drum. A developing cartridge is attachable to and detachable from the drum unit. A developing roller of the developing cartridge is in contact with the photosensitive drum upon attachment of the developing cartridge to the drum unit.
In an image-forming apparatus disclosed in another prior art, a developing cartridge is attachable to a drum cartridge including a photosensitive drum. A developing roller and a photosensitive drum are in contact with each other upon attachment of the developing cartridge to the drum cartridge. The drum cartridge to which the developing cartridge is attached is mounted in a main body of the image-forming apparatus.